double fibonacci_r(double i)
{
	if( i == 1 || i == 2 )
		return 1;
	else return fibonacci_r(i - 1) + fibonacci_r(i - 2);
}

double fibonacci(double i)
{
	double j = 0,l1 = 1,l2 = 1,r_v = 0;
	if( i == 1 || i == 2)
		return 1;
	for(j = 2; j < i ; j++){
		r_v = l1 + l2;
		l1 = l2;
		l2 = r_v;
	}
	return r_v;
}
